by Jarrett Bell, USA TODAY Sports

by Jarrett Bell, USA TODAY Sports

CINCINNATI - Typically while in the midst of the NFL season, the long-distance conversations between Cincinnati Bengals defensive coordinator Mike Zimmer and his son, Adam, ride the wave of Xs and Os and other elements of the game on the field.

Not now.

Adam Zimmer is in his third season as an assistant linebackers coach for the Kansas City Chiefs. Since the tragedy on Saturday - when inside linebacker Jovan Belcher fatally shot his girlfriend, Kasandra Perkins, then drove to the Chiefs headquarters and committed suicide - the phone calls have essentially become father-son therapy sessions.

Adam, who was one of Belcher's position coaches, was at Arrowhead Stadium on Saturday morning when Belcher took his life.

"We used to just talk football," Mike Zimmer told USA TODAY Sports on Wednesday. "Now, it's, 'How are you feeling today? He'll say, 'I'm fine. I'm fine.' But he's the type that you have to reach a little deeper."

Adam's office at the Chiefs headquarters provides a view to the parking lot where the incident unfolded Saturday, when police say that Belcher spoke with coach Romeo Crennel, general manager Scott Pioli and defensive coordinator Gary Gibbs before walking to kneel behind a vehicle and shooting himself in the head.

Crennel, Pioli and Gibbs are among a small group of Chiefs who must undergo mandatory counseling, Troy Vincent, the NFL's vice president of player engagement, told USA TODAY Sports. It is unclear whether Adam Zimmer, 28, is required to have league-mandated counseling, but his supportive father became instantly engaged.

"It's hard," Mike said. "My son was really down. Thank goodness, he wasn't there to see it. I couldn't imagine that."

This is the second time in a little more than three years that the Zimmers have had to come to grips with sudden death. In October, 2009, Vikki Zimmer died of natural causes, forcing father and son to lean on each other.

Shortly after news of the Belcher incident spread, the Zimmers both received text messages from Yolanda Brooks, the Dallas-based psychologist who helped them deal with Vikki's death.

When Mike talked to his son Saturday, Adam told him, "It's kind of like what you said about Mom. Life's not going to stop. We have to keep going."